"verb which expresses repetition of action," 1520s, from French fréquentatif, from Late Latin frequentativus "serving to denote the repetition of an act," from Latin frequentat-, past participle stem of frequentare "visit regularly; do frequently, repeat," from frequentem (see frequent (adj.)). Frequentive is considered incorrect, because -ive adjectives are normally formed on the Latin past participle.